This application incorporates by reference Taiwanese application Serial No. 90114487, filed Jun. 14, 2001.
1. Field of the Invention
The invention relates to a jet ink of magenta. More particularly, the invention relates to a jet ink of magenta with the properties of high light-fastness and high water-fastness.
2. Description of the Related Art
In a color ink-jet printer, the jet inks in the cartridges usually consist of cyan ink, magenta ink, and black ink. Recently, some jet inks of lighter color, such as light magenta, light cyan, and light yellow, are also used to make the printed material more colorful.
The colorants of the inks are mainly divided into the two groups of dye and pigment, wherein the former is more suitable for jet inks due to its property of being more hydrophilic to water. However, the dye""s more hydrophilic property also results in a weaker water-fastness and a weaker light-fastness, which causes the color-fading phenomenon by photo-chemical reaction, such as photolysis, photo-synthesis, and photo-sensitization. Although the pigment has high water-fastness and light-fastness, it has poor property of color lightness, color hue, color chroma, and particle dispersing, which easily causes the pigment to condense, precipitate, and induce the clogging of the nozzle.
The object of the present invention therefore is to provide a jet ink of magenta comprising a reactive red 180, an acid red 52, and a reactive red, wherein the properties of light-fastness and water-fastness are improved greatly and thus, so is the printing quality. The contents of the reactive red 180, acid red 52, and reactive red all range from 0.1 wt % to 10 wt %.
The jet ink of magenta further comprises surfactant, humectant, buffer solution, dispersant, binder, chelating agent, biocide, UV-blocker and water, wherein the surfactant is selected from the group consisting of anionic type, nonionic type, cationic type, and amphoteric type, and its content is less than 20.0 wt %, preferably in the range from 0.1 wt % to 15.0 wt %. The content of humectant is less than 20.0 wt %, preferably in the range from 10 wt % to 20 wt %, and the humectant is a low volatile liquid, such as glycol, ethylene glycol and diethylene glycol. The content of water is about 50.0 wt % to 95.0 wt %.
The above objects and other advantages of the present invention will become more apparent from a detailed description of the preferred embodiments of the present invention.